Highway and traffic safety signs are used in different circumstances to provide a warning to motorists and pedestrians that extra caution should be exercised in the immediate area. Warning signs may be of a permanent nature so as to warn, for example, of a railroad or school crossing. However, work crews are also deployed to temporary location sites as the need arises. When a work site is located on or adjacent a roadway, motorists especially, but also pedestrians need to be advised that greater caution should be exercised and that some deviation in normal traffic patterns may be necessary.
Warning signs employed in these and similar instances may be required for a prolonged period of time as when major road repairs are being conducted, or may be required for only a brief portion of time, such as a portion of a work day. Accordingly, in response to the need for temporary warning signs, various arrangements for so-called “portable” signs and sign stands have been proposed. Originally, the sign panels for such temporary warning signs were made with warning indicia applied to a rigid substrate. Over time, improvements were realized by putting warning indicia on a flexible panel which could be folded or rolled for easy storage. In order to consistently provide the proper display for the indicia, the flexible panel, when brought out of storage, needed to be stretched in a flat, planar configuration. One popular arrangement to provide this feature includes a pair of lightweight flexible ribs which eventually came to be made of fiber reinforced molded polymeric material. The two ribs are typically pivotally joined at their centers to allow the ribs to be rotated between an overlying position for storage and a display position where the ribs are located at 90 degrees to one another, with one rib being vertically aligned and the other being horizontally aligned.
The need therefore arose to support the flexible sign panel from a stand in order to ensure that the vertical rib maintains a desired vertical position despite wind loading and gusts from nearby traveling vehicles. At first, the bottom end of the vertical rib was simply telescopically inserted in a socket, typically made of metal, located at the top of the sign stand. It was found desirable to be able to readily disconnect the sign panel and its supporting ribs from the sign stand, allowing both components to be collapsed for compact storage in a vehicle used to transport workmen and material to and from a roadside job site. However, the bottom end of the vertical rib tended to become frayed, splitting or cracking due to the repeated contact with the sign stand base.
U.S. Pat. No. 4,888,894 provided a plastic pocket to cover the bottom end of the vertical rib, shielding and protecting the rib while the pocket is telescopically inserted and removed from the sign stand base. U.S. Pat. No. 4,888,894 also provided a releasable securement arrangement for securing the plastic pocket and enhance the sign panel in the sign stand. However, the arrangement has been found inadequate in a number of ways. For example, the construction of the socket or pocket receiver portion of the sign stand is relatively massive, requiring a number of special machining operations for its manufacture and assembly. Also, the socket body was welded to form an open ended tubular shape, only a portion of which was filled with the plastic pocket. Most of the upper end of the socket is open to the element and hence tend to corrode, accumulates rain, sleet and other moisture which becomes trapped in the interior of the socket assembly.
The release lever of U.S. Pat. No. 4,888,894 is actuated in an upward direction to allow release of the pocket and hence the sign panel, contrary to an intuitive inclination to the depress the operating level for such purpose. Further, the socket was constructed in such a way that only minimal points of contact were made between the plastic pocket and the surrounding metal structure of the socket holding the plastic pocket in position. The lever operated release includes a metallic hook portion which is spring loaded for lever action and which is deflected by the plastic pocket during insertion of the pocket in the sign stand. The metal to plastic contact, especially when repeated during numerous set up and take down operations has been found to result in accelerated wear of the plastic pocket. Further, the metal to plastic contact becomes more difficult as the metal surface contacting the plastic pocket has increased friction characteristics caused by abrasion of its surface and corrosion from moisture and roadside salt spray during winter months. Accordingly, the need has arisen for an improved sign stand support for temporary signage display for warning and other types of indicia.